Die-casting apparatus



Jan. 10, 1950 c. c. vEALE DIE CASTING APPARATUS 2 Sheets-Sheet l Filed Nov. l1, 1943 5 6 L2 2 4 f 2 %-i r-f|- u u m euo/rw 0 2 2 s Il n .r T-- -2@ .lllmwhHHHHNM-H HNINI|I|IIMH\\\ IIL T L ,f l l ./NVENTOE C. C. VEALE er 44..; z. A7@

TOENEY Jan. l0, 1950 c. c. vEALE DIE CASTING APPARATUS 2 Sheets-Sheet 2 Filed NOV. ll, 1943 E m w. w

i C. C. VEHLE @Y Arras/Vey Patented dan. l0, 1950 DIE-CASTING APPARATUS Charles C. Veale, Wheaton,

Ill., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application November 11, 1943, Serial No. 599,866

1 Claim.

This invention relates to die casting apparatus and more particularly to mechanisms for controlling the operation of die casting machines.

It is an object of the present invention to provide a simple, reliable and automatic apparatus for controlling the sequence of operations of a die casting machine.

In accordance with one embodiment of the invention, cooperating hydraulic and electric circuits are so arranged that by the manipulation of a single valve which controls the supply of uid under pressure to the ram of a die operating mechanism, a complete cycle of operation of the die casting apparatus is effected. In this cycle, the dies of the apparatus close, an injection plunger is advanced a predetermined distance at a relatively slow speed, is held stationary for a short interval, is then advanced relatively rapidly to make a die casting shot and is, after a predetermined interval, reset to its original position.

A complete understanding of the invention may be had by reference to the following detailed description when considered in conjunction with the accompanying drawings, wherein Fig. 1 is a front elevational view of a die casting machine embodying the structural features of the presentinvention, and

Fig. 2 is a diagrammatic view of the electrical and hydraulic circuits constituting the preferred embodiment of the present invention. A

In the drawings, particular reference being rst had to Fig. 1, there is shown a die casting machine including framework, designated generally by the numeral I0, in which a cross head II may be reciprocated by a piston I2, which is adapted to be actuated by fluid under pressure admitted to a cylinder I3 through either a port I4 or a port I5. The cross head II has suitably fixed to it an upper movable die member I5 for cooperation with a stationary die member I1 seated upon a bolster I8, which is, in turn, suitably mounted in the framework I0. Extending partly under the bolster I8 is a melting pot I9, in which there is formed a gooseneck 20 for directing die casting material upwardly through a nozzle 2| to the die members I 6 and Il. The gooseneck 20 is in communication with a shot cylinder 22, into which die casting material may pass through suitable apertures 23 for transference to the dies. The, shot cylinder 22 has a shot plunger 24 positioned therein, which may be-reciprocated by a head member 25, to which the shot plunger may be suitably connected by means of a connecting member 26. The mecha.-

nism described thus far is shown in detail in the co-pending application of George L. Cherry and Charles C. Veale, Serial No. 493,079,l filed August 10, 1943, now matured into Patent No. 2,393,588 wherein various features of the mechanism are described specifically and claimed.` The head member 25 is adapted to be reciprocated by a piston rod 3l! (Fig. 2) and will, at predetermined times, to be described more in detail hereinafter, actuate a switch 21, which may be enclosed in a suitable housing 28 (Fig. 1) attached to the framework I0, being suitably mounted on a housing 29 (Fig. 1) which encloses the various actuating and controlling means shown in Fig. 2. Mounted within the housing 29 (Fig. 1) are a pair of aligned cylinders 35 and 36, in which pistons 3l and 38, respectively, are reciprocated. The piston 38 has a piston rod 39 attached to it for normally limiting the upward movement of the piston 3l when the piston 38 is in the position shown in Fig. 2. The piston 38 is normally held in the position shown in Fig. 2 by iluid under pressure from a suitable source (not shown) directed through a valve 40 and entrance port 4I to the upper end of the cylinder 33. If it is desired to move the melting pot I9 for any reason, the plunger 24 may be Withdrawn from the cylinder 22 by reversing the valve 40 and permitting fluid under pressure acting against the underside of the piston 31 to move the piston 38 upwardly, thus to withdraw the plunger24 completely from the shot cylinder 22. In the normal operation of the apparatus, the piston 38 and piston rod 39 are always maintained in the position shown, where they will limit the upward movement of the shot plunger 24 to approximately that shown in Fig. 1, where its lower end is just above the inlet apertures 23 from the melting pot to the shot cylinder 22. It be noted at this time that if fluid under the same pressure is fed into the opposite ends of the cylinder 35, the piston 31 will be moved downwardly due to the differential pressure exerted thereon because of the difference in effective area of the top and bottom faces of the piston 31.

The cylinder 35 may be supplied with fluid under pressure through either an upper entrance port 42 or lower entrance port 43 upon the proper manipulation of a pair of` slide valve members 44 and 45 slidably positioned in a valve block 45. The slide valve member 44 is provided with a pair of relatively small passageways 50 and 6I formed in it and a pair of relatively large passageways 52 and 63, through which fluid under pressure may be selectively directed to the should the passageways ports l2 and I3, depending upon the position of the slide valve member ll within the valve block 46. The slide valve member l5 is provided with a pair of relatively large passageways 54 and 55 and a relatively small passageway 86, through which fluid under pressure may be directed through passageways in the block 4G and through in the slide valve member 40.

Fluid under pressure from a suitable source (not shown) is supplied to a large entrance po 91 and a small entrance port 88 in the valve block I8 and the iluid driven out of the cylinder 35 may return to the source through an exit port 69 formed in the valve block I8.

The position of the slide valves Il and 45 in the valve block I6 may be controlled by a pair of solenoid-actuated slide valves, designated generally by the numerals 15 and 16. The solenoidactuated slide valves 15 and 16 have entrance ports 11 and 18, respectively, connected to the source of fluid under pressure and have exhaust ports 'I9 and 80 and 8| and 82, respectively, which are connected to return pipes 83 and 84, respectively, for conducting spent fluid back to the source of iiuid under pressure. The valve 15 has a slide valve 85, which may be shifted to either one of two positions upon the selective energization of a solenoid 88 or a solenoid 81 and, similarly, the valve 16 has a slide valve member 88 which may be selectively shifted to either one of two positions upon the selective energization of the solenoids 89 and 90. When the slide valve member 85 is in the position shown in Fig. 2, fluid under pressure will be directed through the entrance port 11 to the slide valve member 85 and through a pipe 9| against the upper end of the slide valve member ll in the valve block 46 and fluid in the lower end of the valve block 46 will pass out through pipe 92 past the slide valve member 85 through exhaust port 80 and thus back to the source of fluid under pressure. When the position of the slide valve member 85 is reversed from that shown in Fig. 2, the slide valve member 4I will be shifted to its upper position opposite to that shown 'in Fig. 2 due to the shifting of the slide valve member 85 to interconnect the entrance port 11 thereof with pipe'92 and to interconnect pipe 9| with the exhaust port 19.

In the position shown, the slide valve member 3l interconnects the entrance port 18 with pipe 93 and thus iluid under pressure will be forced against the upper end of the slide valve member 45 in valve block I6.4 When the slide valve member 88 is in the position shown, fluid entrapped beneath the lower end of the slide valve member l5 may be forced through a pipe 93 and through valve 15 to an exhaust port 82 and thusback to the source of fluid under pressure.

Power for energizing the solenoids 80, 81, 89 and 90 is supplied from a suitable current source through a main control switch |02, which may be closed to prepare the apparatus for operation. The slide valves 15 and 10 are of the type which may be shifted from one position to the other and when soV shifted, will remain in their shifted position until the opposite one of the solenoids associated therewith is energized. Solenoid 8i is adapted to be energized upon the closure of a plunger-operated switch |03, solenoid 81 is adapted to be energized upon closure of a switch |03, solenoid 89 is adapted to be energized upon the closure of a switch forming part of a time delay relay |08, and solenoid 9| is adapted to be energized upon the closure 4 of the switch 21. The time of operation of the various switches which close the solenoids will be described more in detail with the description of the operation of the apparatus.

Fluid under pressure may be supplied from a suitable source. not shown, through a port |01 and through a manually operable main valve |08 to move the piston I2 upwardly or downwardly to open or close the dies of the apparatus by raising or lowering the upper die member I6. In the diagrammatic illustration in Fig. 2, the piston |2 has an enlarged head portion |09, which is shown in its upper position, to which it has been raised by shifting the valve |08 to permit the passage of fluid under pressure therewith and through the port I4 to the underside of the piston head |09, a suitable packing gland ||0 being provided to close that portion of the lower end of the cylinder I3 which is not filled by the piston |2. The port Il is connected to the valve |08 by means of a pipe I II in communication with which there is a relatively small pipe ||2 which leads to the upper end of a control cylinder H3. The control cylinder ||3 has a piston ||0 in it, which serves to actuate a piston rod IIS carrying at its lower end a valve member H6 which is normally urged to engage a valve seat ||1 in the cylinder I3 by a compression spring ||8 interposed between an upper surface of the cylinder I3 and a disc ||9 attached to the piston rod H5. The interior of the cylinder i3 has a bore |25 which conforms to the size of the valve seat II1,

piston head |09 and it is gradually reduced to a relative small bore |28, into which a reduced portion |21 of the piston I2 may move a short dis tance. A bleeder passage |28 interconnects the small bore |26 with the upper portion of the large bore |25, so that these two chambers are in communication. The purpose of this' construction will become apparent as the description progrosses. The lower end of the cylinder ||3 has a pipe |29 communicating therewith, which is in communication by when the valve |08 is moved to the position opposite to that shown sure supplied through port |01 will pass out through port I3| into pipes |30 and |29 and reverse the position of the piston III in the cylinder |I3. The pipe |30 also has a pipe |32 in communication therewith which extends to a control cylinder |33 having a piston |34 in it which is normally urged to its downward position, as shown in Fig. 2, by a compression spring |35, but which may be moved upwardly against the action of the spring |35 to, through the action of a plunger |36, close the plunger-actuating switch |03. Seated in the port I5 is a valve member |31, which is normally urged to seat against a valve seat |38 by a compression spring |39 engaging an upper surface of the cylinder I3 and bearing against a disc |40 attached to a valve stem |4'I which carries the valve member |31. The cylinder |3 is provided with an upper chamber |02, in which the compression springs I|8 and |39 are positioned and this chamber may be sealed from communication with the small bore |25 of the cylinder I3 by the valve head IIB. However, when the valve head ||8 is disengaged from the any fluid which may be in the upper portion of the cylinder I3 will be permitted to pass out through the chamber |42 to a pipe |43 which returns the fluid to the fluid pressure source.

la The cross head carries a switch-actuating with a pipe |30 interconnecting Athe port I5 and a port I3| in the valve |08, wherein Fig. 2, fluid under pres-l member |44, which is adapted to close the switch |04 when the cross head II moves downwardly and, similarly, the head member on the piston rod carries ,aswitch-actuating member |45, which is adapted to close the switch 21. In this manner, these two switches may be closed to supply current from the source |0| through the main switch |02 to their respective solenoids. The switch |03, when closed by the plunger |36, will supply power to the solenoid 86 and also to the time delay relay |06, thus to initiate the operation of the time delay relay |06 at the same time that the solenoid 86 is energized. The time delay relay |06 is set to close its switch |05 a predetermined length of time after the switch |03 closes and when switch |05 closes, it will energize its associated solenoid 89.

A more complete understanding of the apparatus may be had by reference to the following brief description of the mode of operation thereof. The closure of the switch |02 and the initiation of the operation of the mechanism for supplying uid under pressure to the various parts of the apparatus will place the apparatus in condition for operation. After the melting pot I9 is in the proper position, and the piston 38 has been set in the position shown in Fig. 2,

1 and a supply of molten metal is in the melting pot I9, the apparatus may be operated to die cast parts'conforming to the shape of the die members I6 and I1. The operation of the apparatus is initiated by reversing the valve |08 from the position shown in Fig. 2. When the valve |08' is moved to the position opposite to that shown in Fig. 2, fluid under pressure through port |01 will be directed to the pipe |30 and fluid in the lower end of the cylinder I2 will be permitted to escape through the valve |08 in its reverse position. Fluid under pressure being admitted through the pipe |30, will pass first through port I5 and will force the valve head |31 downwardly against the action of its associated spring |39, to pass into the upper end of the cylinder I3. plying of fluid under pressure through the entrance port I5, uid under pressure will be supplied through pipe I29 to raise the piston I I4 and the iluid in the upper end of cylinder II 3 will pass through pipes ||2 and |I and valve |08 back to the source of fluid under pressure.

In this manner, the valve head I I6 will be seated in the valve seat |I1 and the uid admitted to the upper end of the cylinder I3 will not be permitted to pass out through chamber |42 and pipe |43, but will actuate the piston head |09 and start its downward movement. The piston |34 in the cylinder |33, will not, at this time, be operated since the compression spring is suiliciently strong to prevent the piston |34 from moving upwardly until the upper die member I6 engages the stationary die member' I1 and pressure is thus built up `within the cylinder |25. As the piston head I 09, piston I2 and the cross head move downwardly, the switch-actuating member |44 will, in its movement downwardly with the head II, momentarily close switch |04 to supply power for energizing the solenoid 81. Energization of' solenoid 81 will shift the slide valve member 85 from the position shown to its lowermost position and fluid under pressure supplied through entrance port 11 will be directed through pipe 92 to the underside of the slide valve member 44, thereby to shift it to its upper position. When the slide valve member 44 is shifted to its upper position, passagewayv 6| and close a switch 21,

solenoid 90 and thereby shift the slide valve` Simultaneously with the suptherein will interconnect the small entrance port 68 with the lower entrance port 43 of cylinder 35 and passageway 62 will connect a large entrance port 61 through passageway 66 to entrance port 42 of the cylinder 35. In this manner, iluid under pressure will be supplied to both the upper and lower 'surfaces of the piston 31. Since the upper effective surface ar'ea of the piston 31 is larger than the lower surface thereof, piston 31 will be moved downwardly slightly by the difference in effective pressure of the tluid supplied to the opposite sides thereof and will carry the head member 25 downwardly to move the shot plunger 24 below the apertures 23 and thus entrap a shot of molten metal in the gooseneck 20. As the head member 25 moves downwardly, the switchactuating member |45 will momentarily engage thus to supply power to the member 88 from the position shown to a position opposite to that shown where iiuid under pressure through the entrance port 19 will be directed to the lower surface of the slide valve member 45 to raise the slide valve member 45. It will be understood that when the slide valve member 45 moves upwardly, the fluid in the upper end ofthe valve block 46 will be forced through the pipe 93 and exhaust port 0| and back to the fluid source and that, similarly, when the slide valve member 44 moves upwardly, fluid between the upper end thereof and the top wall of the block 46 will be directed through the pipe 9| and valve 15 through exhaust port 19. When the slide valve member 45 is moved upwardly, all of the passages in the block 46 communicating with the entrance ports 61 and 68 and exhaust'ports 69 will be blocked by either slide valve member 44 or slide valve member- 45 and this condition will prevail until the upper die member I6 tightly engages the stationary die member I1 and pressure builds up in the pipe |30 to such an extent that the piston |34 will be raised. As soon as the piston |34 is raised, it will close switch |03 through its plunger |36 and will energize solenoid 86, thus to reverse the position of the slide valve member and return it to the position shown in Fig. 2. When slide valve member 85 is moved back to the position shown in Fig. 2, entrance port 61 will be interconnected with upper entrance port 42 of the cylinder 35 through the large passageways 64 and 62 in the slide valve members 45 and 44, respectively. Similarly, port 43 of cylinder 35 will be connected to exhaust port 69 through large passageways 63 and 65 in slide valve members 44 and 45. Thus, a relatively large amount of iiuid under pressure will be directed against the upper surface of the piston 31 to force the piston 31 rapidly downwardly to inject a portion of the molten metal trapped in the gooseneck up into the' die members I6 and I1.

The construction of the cylinder I3 and valve members IIS and |31 is such that, when pressure in the upper end of the cylinder and in pipe |30 is at its highest point, valve member |31 will seat against valve seat |39 and valve member |I6 will seat against valve seat I I1, thus sealing the upper end of the cylinder. When the shot plunger 24 injects the molten metal into the die cavity, piston head |09 will tend to move upwardly, but the head of fluid in the upper end of the cylinder I3 will only force the valve members ||6 and |31 more firmly into engagement with their associated valve seats and will prevent the upward movement of the die member I6.

As the switch |03 was closed to initiate the operation oi the shot plunger in injecting a shot into the die member, the circuit to time delay relay |06 was also completed, thus initiating operation oi this relay, and after a predetermined selected interval, relay |06 will close its switch |05, thus to supply current to solenoid 39 to effect the return of slide valve member 38 to its normal position, as shown in Fig. 2. When the slide valve member 8B returns to the position shown in Fig. 2, slide valve member 85 having been returned to its upper position, the apparatus will be restored to the condition shown in Fig. 2, where the upper entrance port 42 of cylinder 43 will be in communication with the exhaust port 69 in the block 46 and where entrance port 66 will be in communication through passageways 65 and 60 with the port 43, thus to return the shot plunger to its normal position by raising the piston 31. In this manner, the portions of the apparatus which inject the shot of molten metal between the die members I6 and |1 will be restored to normal condition and the return of the valve |08 to the position shown in Fig. 2 will restore the die i6 to its upper position in the following manner: When the valve |08 is moved from the position opposite to that shown in Fig. 2, back to the position shown in Fig. 2, iiuid under pressure will be directed through port |61 to pipes Hi and ||2. The fluid under pressure directed through the port I4 from pipe will be ineffective to raise the piston head |09 due to the fact that the upper end of the cylinder i3 has been closed off from communication with the chamber |42 by the valve member I6 and the valve member |31 has blocked the flow of fluid out of the cylinder I3 through port i5. Therefore, the first operation that takes piace is the return of the piston |4 to the position shown due to the supply of pressure to the upper end thereof and the return of iluid to the lower end thereof through pipe 29 and pipe i30. When piston |44 moves downwardly, the upper end of the cylinder i3' will be in communication with the chamber mi and iiuid may thus pass from the upper end of the cylinder i3 out through the pipe |63 and back to the fluid source. in this manner, the piston l2 will be moved upwardly quite rapidly until it approaches the upper end of its travel, at which time the reduced portion |21 of the piston head |29 will enter the small bore i26 and the escape of iiuid from the upper end of the cylinder i3 will all be through the bleeder passage |28, thus to cushion the upper movement of the piston I2. As soon as the valve |08 is moved back to the piston shown in Fig. 2, the pressure against the piston |34 will, of course, be released and switch |03 will be opened, thus to restore the entire apparatus to the position shown in Fig. 2.

to cause retraction of said It should be noted that the switch-actuating members |44 and |45 ontbe heads il and 25 are ineilective to operate their respective switches on the upward movement of the heads.

What is claimed is:

An apparatus for lnj ecting casting material into a mold having a cylinder and fpiston for closing the mold and a hydraulic cylinder and piston for injecting material into the mold, comprising hydraulic means for moving the molding piston to close the mold, means for locking the mold-closingl piston at the end of the closing movement, a rst two-position valve in the hydraulic lines to the injection cylinder and movable to its second position in response to the movement of said closing piston to actuate the injection piston to a ready position, a second two-position valve in the hydraulic lines leading to said iirst two-position valve and movable to its second position in response to the movement of the injection piston to its ready position to lock the injection piston in place, an auxiliary piston connected to the mold closing cylinder so that it is responsive to the building up of a hydraulic pressure on the mold-closing piston after closing of the mold, said auxiliary piston being connected to the operating mechanism of said first two-position valve first two-position valve to its rst position, said retraction of the first two-position valve being effective to unlock the injection piston and initiate a rapid actuation of the injection piston, a time delay device operated by said auxiliary piston for causing retraction of said second two-position valve to its rst position, said retraction oi the second two-position valve being effective for restoring the injection piston to normal position, and a inanuallir operated valve for unlocking and restoring the molding piston to normal position.

. CHARLES C. VEALE.

REFERENCES CITED STATES PATENTS Numr Name Date 1661.342 Rick June 5, i934 2,318,021 Curtiss May 17, 1938 2,182,059 Schwartz Dec. 5, 1939 2,210,665 Harrington Aug. 6, 1940 2,214,308 Polak Sept. 10, 1940 2,293,087 Tann Aug. i8, i942 2,306,323 Schoepfiin et a1 Dec. 22, 1942 2,334,372 Abbott et al Nov. 16, 1943 2,363,759 Waldie Nov. 28, 1944 

